diff --git a/workflow/engine/classes/model/OutputDocument.php b/workflow/engine/classes/model/OutputDocument.php
index f34bb9651..546466559 100755
--- a/workflow/engine/classes/model/OutputDocument.php
+++ b/workflow/engine/classes/model/OutputDocument.php
@@ -922,7 +922,7 @@ class OutputDocument extends BaseOutputDocument
         define('PATH_OUTPUT_FILE_DIRECTORY', PATH_HTML . 'files/' . $_SESSION['APPLICATION'] . '/outdocs/');
         G::verifyPath(PATH_OUTPUT_FILE_DIRECTORY, true);
         require_once (PATH_THIRDPARTY . 'html2ps_pdf/config.inc.php');
-        require_once (PATH_THIRDPARTY . 'html2ps_pdf/pipeline.factory.class.php');
+        @require_once (PATH_THIRDPARTY . 'html2ps_pdf/pipeline.factory.class.php');
 
         parse_config_file(PATH_THIRDPARTY . 'html2ps_pdf/html2ps.config');